Vertical lift door



Feb. 24, 1959 Filed Sept. 30. 1953 A. E. FENTIMAN VERTICAL LIFT DOOR 2 Sheets-Sheet l Inventor ARTHUR E FENTIMAN MQM Att orney Inventor t orney A. E. FENTIMAN VERTICAL LIFT DOOR 2 Sheets-Sheet 2 FIG. 3.

ARTHUR E FENT IMAN By At Feb. 24, 1959 Filed Sept. 30, 1955 United States Patent" 2,874,422 VERTICAL LIFT noon Arthur E. Fentiman, Ottawa, Ontario, Canada, assignor to F. Fentiman & Sons, Ltd., Ottawa, Ontario, Canada Application September 30, 1953, Serial No. 383,236

7 Claims. (Cl. 20-19) This invention relates to improvements in a vertical lift door. structure of a type suitable for manufacturing plants, warehouses, garages and like structures.

An object of the invention is to provide a sectionalized door structure wherein the load of the door on the hoisting mechanism is constant throughout the entire lifting operation.

A further object of the invention is to provide .such a sectionalized, vertical lift door structure wherein the constant hoisting load is substantially balanced at all times by a counterweightv so that a minimum of power is required to raise or lower it.

A further object of the invention is to provide a counter balanced, vertical lift sectionalized door structure, the lower door section of which, composed of a plurality ofindividually removable panels, may continue to operate in a normal and balanced way even when a damaged panel and a corresponding weight on the counter balance have been removed, the lifting mechanism for the entire door being through connections located at the ends of the top of the lower door section. l A still further object of the invention is the provision of a vertical lift sectionalized door structure of the nature and for the purpose described that is characterized by structural simplicity, durability and relatively low cost of production, installation and operation whereby the same is rendered commercially desirable.

To the accomplishment of these and related objects as shall'become apparent as the description proceeds, the invention resides in the construction, combination and arrangement of. parts as shall be hereinafter more fully described, illustrated in the accompanying drawings, and pointed out in theclaims hereunto appended.

The invention will be best understood and can be more clearly described when reference is had to the drawings forming a part of this disclosure wherein like characters indicate like parts throughout the several views.

In the drawings: a

' Figure 1 is an elevation, of a preferred embodiment or the door, as seen from the inside of a building;

Figure 2 is an enlarged transverse vertical section, as taken on line 22 of Figure 1; t

Figures 3 and 4 are yet further enlarged transverse horizontal and vertical sections respectively, as taken on lines 33 and 4-4 of Figure 1; and

Figure 5 is an elevational detail of the cradle chain and sprocket arrangement by which the upper and lower door sections are connected, as seen from the right of Figure 4.

Having particular reference now to the drawings, the door opening A, of an industrial plant, warehouse, garage or other building designated at B is shown having track means comprising a laterally spaced pair of channellike tracks 1 running up each side of the door opening and extending, on the inside of the building, above the top of the door opening by at least half' the height of such opening. The door C is composed of two'separate c 2, 4,42 1C 87 z parts,namely an upper door section 2 and a lower door section 3, each extending horizontally for the full width of the door opening A and each of a height atleastone half that of the opening. These two door sections slide vertically in the side tracks 1, the upper door section in the outer tracks and the lower door section in the inner tracks and both door sections can be raised completely clear above the door opening because of the upward extension of the tracks hereinbefore mentioned but it will be apparent that it is not necessary to continue the outer tracks for the upper door section below the normal level of the bottom of such upper door section which is about midway of the height of the door opening.

Each of the door sections 2 and 3 shown in the accompanying drawings consists of three separable horizontal parts or panel sections 4 that fit at their opposite ends into outside vertically disposed angles or side plates 5, clearly shown in Figures 3 and 5, and are secured thereto by nuts and bolts 6 transversely therethrough. To render the panels 4 of the lower door section 3 readily interchangeable, since they are more liable to be damaged, wingnuts 60 are used. Additionally, metal straps 7 bolted later-ally to adjacentpanels of a door section are provided at suitably spaced intervals but in the case of the lower door section these are of two part hinge-like construction as 7a with a connecting pin 7b to allow of their ready separation.

Each of the door sections 2 and 3 is provided at top and bottom of each side with roller means including a horizontal, longitudinally projecting axle or shaft 8 with a roller 9 on its outer end for engagement in the channel-like tracks 1.

The angles 5 on opposite ends of the lower door section 3 extend upwardly above the top of the section as seen in Figures 3, 4 and 5 and are each capped with a horizontal gusset plate 10 securely welded thereon that has a longitudinal extension 10a projecting. beyond the end of the door section. The lifting mechanism is associ-ated with this part; the main lift chains 11 at each side of the door rise from an anchor stud 12 on the under side of the gusset plate 10 at a point located inside the angle and passing over pulleys 13 located'on the inside of the building B ,above the level of thetop of the door sections when fully open, connect with a balance weight 14 suspended in a housing or cover 15 at one side of the door. This weight includes a number of removable units 14a each equal to the weight of one panel 4 of the lower door section 3 so that if one or two of such panels should be damaged, it orthey may be taken out and a corresponding weight removed from the balance weight 14 and thus a perfect balance is maintained even when a part of the door is temporarily missing.

The pulley 13 at the side where the weight 14 is located, is a double sprocket to carry both of the chains 11 and may be power driven by a chain 16 from a suitable electric motor 17 with a hand release chain 18 and manually operated chain 19, as is common practice and do not of themselves form a part of the present invention.

The lifting of the upper door section involves the principle of the moving pulley with the inherent 2-1 mechanical advantage that is here employed to cut in half its load, its speed of travel and the distance moved. From an anchor stud 20 secured to a bracket 21 in each of the outer tracks 1 at a point above the door opening a cradle chain 22 passes under a sprocket wheel 23 rotatably mounted on the shaft 8 at the lower corner of the upper door section 2, at each side thereof, and is connected by a stud bolt 24 to the overhanging projecting end 10a.of the gusset plate 10 on the lower door section 3 at its re- Patented Feb. 24, 1959 lifting operation and by reducing its speed because of the shorter distance to he travelled cuts the load to one half. While most verticle lift doors consisting of two or more horizontal sections operate to raise the lowermost section until it is opposite the next higher and then double the load to raise both sections, and so on, with a variable load on the motor and requiring a maximum power sufficient to lift the entire load of the door; this cradle chain door arrangement equalizes the door load on the motor throughout the full period of the lifting operation and thereby enables the perfect balancing of the load at all times by the counter balance of fixed weight but it'also lessens the operating load of the door to that of 1% door sections instead of 2. However, because of the perfect balancing of load that is thus made possible, a motor of very limited power is all that is needed.

Furthermore, it will be noted that while most doors have the hoisting cables attached to the bottom of the lower door section, the top-lift achieved in the present invention by anchoring the lift chains 11 to the gusset atop the upstanding angles 5 of the lower door section 3 and at a point lying beyond the end of the door panel and between the parallel planes of the lateral faces of the door greatly reduce the possibility of damage to the lifting mechanism and enables it to function properly even if and when the bottom part of the door section be damaged.

From the foregoing description taken in connection with the accompanying drawings, it will be manifest that a vertical lift door is provided that will fulfil all the necessary requirements of such a device, but as many changes could be made in the above description and many apparaently widely different embodiments of the invention may be constructed within the scope of the appended claims, without departing from the spirit or scope thereof, it is intended that all matters contained in the said accompanying specification and drawings shall be interpreted as illustrative and not in a limitative or restrictive sense.

Having thus described the invention what is claimed as new 1s:

1. In a door structure for mounting within the doorway of a building, the combination of a vertical lift door extending across said doorway and having an upper door section and a lower door section, track means mounted within said doorway, side plates removably secured to the sides of said upper and lower door sections and supporting said door sections therebetween, roller means secured to said side plates and engaging said track means, and a lifting mechanism operatively connected with said side plates.

2. The combination as specified in claim 1, wherein said track means comprises a pair of spaced-apart track channels mounted at each side of said doorway, the roller means secured to the side plates of said upper door section engaging one of said pair of track channels and the roller means secured to the side plates of said lower door section engaging the other of said pair of track channels, said roller means supporting said door sections in a spaced relationship, permitting facile removal of either of said door sections without disturbing the other.

3. In a door structure for mounting within the doorway of a building, the combination of a vertical lift door extending across said doorway and having an upper door section and a lower door section; track means mounted within said doorway; vertically disposed angle members removably secured to the sides of said upper and lower d r sec on and sup o n sa d oor se t ons therebetween; roller means secured to said vertically disposed angle members adjacent the uppermost and lowermost portions of said upper and lower door sections, each of said roller means including a shaft secured to said vertically disposed angle member and projecting horizontally outward therefrom, and a roller mounted on said shaft adjacent the outermost end thereof for engagement with said track means; and a lifting mechanism operatively connected with saidvertically disposed angle members, said lifting mechanism comprising pulleys rotatably mounted on the shafts of said roller means adjacent the lowermost portion of the vertically disposed angle members secured to the upper door section, said pulleys being disposed outwardly of the sides of said upper door section, between said rollers and said vertically disposed angle members, lift chains connected to the uppermost portion of the vertically disposed angle members secured to said lower door section, and cradle chains anchored at one end to the building above the door and the opening, outwardly of said vertically disposed angle members, said cradle chains passing partly around said pulleys and con nected by their other ends to the vertically disposed angle members of said lower door section at a position out wardly of said vertically disposed angle members, so that said upper and lower door sections may be easily removed from between said vertically disposed angle members without disturbing any of the other door structure.

4. In a door structure for mounting within the doorway of a building, the combination of a vertical door extending across said doorway and having an upper door section and a lower door section; a pair of track channels mounted at each side of said doorway; side plates secured to the sides of said upper and lower door sec? tions and supporting said door sections therebetween, said side plates secured to said upper door section extend ing substantially the height of said upper door section, and said side plates secured to said lower door section having one end thereof adjacent the lowermost portion of said lower door section and extending above the up ermost portion of said lower door section; roller means secured to said side plates adjacent the uppermost and lowermost portions of said upper and lower door sections, each of said roller means including a shaft secured to said side plate and projecting horizontally outward therefrom, and a roller mounted on said shaft adjacent the outermost end thereof for engagement with said track means; and a lifting mechanism operatively connected with said side plates, said lifting mechanism comprising pulleys rotatably mounted on the shafts of said roller means adjacent the lowermost portion of the side plates secured to the upper door section, said pulleys being disposed outwardly of the sides of said upper door section, between said rollers and said side plates, lift chains connected to the uppermost portion of the side plates secured to said lower door section, and cradle chains anchored at one end to the building above the door opening outwardly of said side plates, said cradle chains passing partly around said pulleys and connected by their other ends to the upper portion of said side plates connected to said lower door section at a position outwardly of said side plates, so that said upper and lower door sections may be easily removed from said side plates without disturbing any of the other door structure.

5. In a door structure for mounting within the doorway of a building, the combination of a vertical lift door extending across said doorway and having an upper door section and a lower door section; a pair of track channels mounted at each side of said doorway; side plates secured to the sides of said upper and lower door sections, the side plates secured to said lower door section extending above the upper edge of said lower door section and each there provided with horizontal gusset plates extending both inwardly of and outwardly of the sides of the lower door section; roller means secured to said side plates adjacent the uppermost and lowermost portions of said upper and lower door sections, each of said roller means including a shaft secured to said side plate and projecting horizontally outward therefrom, and a roller mounted on said shaft adjacent the outermost end thereof for engagement with said track channels; and a lifting mechanism operatively connected with said side plates, said lifting mechanism comprising pulleys rotatably mounted on the shafts of said roller means adjacent the lowermost portion of the side plates secured to the upper door section, said pulleys being disposed outwardly of the sides of said upper door section, between said rollers and said side plates, lift chains connected to the uppermost surface of the horizontal gussets of the side plates secured to said lower door section, and cradle chains anchored at one end to the building above the door opening, outwardly of said side plates, said cradle chains passing partly around said pulleys and connected by their other ends to the undersurface of the horizontal gusset plates at a position outwardly of said side plates, so that said upper and lower door sections may be easily removed from said side plates without disturbing any of the other door structure.

6. In a door structure for mounting within the doorway of a building, the combination of a vertical lift door extending across said doorway and having an upper door section and a lower door section; a pair of track channels mounted at each side of said doorway and extending above the top of said doorway on the inside of said building; roller means secured to the sides of said upper and lower door sections adjacent the uppermost and lowermost portions thereof, each of said roller means including a shaft secured to said door section and projecting horizontally outward therefrom, and a roller mounted on said shaft adjacent the outermost end there of for engagement with said track channels; and a lifting mechanism operatively connected with said upper and lower door sections, said lifting mechanism comprising pulleys rotatably mounted on the shafts of said roller means adjacent the lowermost portion of the upper door section, said pulleys being disposed to the sides of I said upper door section, between saidv rollers and the side of said door section, lift chains connected to said lower door section, adjacent the sides and at the uppermost portion thereof, and cradle chains anchored by one end to the building above the door opening, outwardly of the sides of said upper and lower door sections, said cradle chains passing partly around said pulleys on the upper door section and connected by their other ends to the sides of the uppermost portion of the lower door section.

7. In a door structure for mounting within the doorway of a building, the combination of upper and lower door sections extending across said doorway, said lower door section comprising a plurality of separable panel sections removably secured to a pair of side plates, said side plates supporting said separable panel sections therebetween as a unitary door section, each of said side plates having an upward extension extending above said separable panel sections; a pair of track channels mounted at opposite sides of said doorway; roller means secured to said upper and lower door sections, one of said pair of track channels receiving the roller means secured to said lower door section and the other of said pair of track channels receiving the roller means secured to said upper door section; and a lifting mechanism for raising and lowering said door sections, said lifting mechanism being operatively connected to said upper door section and connected to said upward extension of said side plates of said'lower door section outwardly of and above said separable panel sections, so that the said separable panel sections of said lower door section may be removed and replaced without disturbing any of the other door structure.

References Cited in the file of this patent UNITED STATES PATENTS 757,179 Cross Apr. 12, 1904 1,250,992 Dost Dec. 25, 1917 1,332,956 Rush Mar. 9, 1920 1,710,108 Orrock Apr. 23, 1929 2,207,148 Hall July 9, 1940 2,399,169 Crawford Apr. 30, 1946 

